1. Field of the Invention
The present invention pertains to methods and apparatus for selectively adjusting and maintaining the height of an object, say, for example, for maintaining a displacement within a certain range above a rising or falling reference. More particularly, the present invention pertains to techniques for raising and lowering, as well as anchoring in position, objects such as decks, or platforms, for example, to maintain such objects a given distance, or within a given range of distances, above the rising or falling surface of a body of water. The present invention finds particular application to decks and the like to be supported over natural bodies of water.
2. Brief Description of Prior Art
Platforms and other objects such as pier decks that are used positioned above a natural body of water may be subject to large discrepancies in the level of the water with the result that the distance from the deck to the surface of the water may become extremely large as the water level falls, resulting in great inconvenience in using the pier. Similarly, in the case of rising water, the deck may be swamped and covered with the water and even damaged or destroyed.
Floating piers are known, containing sufficient buoyant devices to keep the pier floating on the surface of the body of water while constraints in the form of piles and/or lines to the shore retain the pier generally in a desired location relative to the shore while the pier rises and falls with the level of the body of water. However, a floating pier is vulnerable to wave action, which can not only damage the mechanism used to constrain the pier but also swamp and possibly destroy the pier in the case of high seas.
Other known techniques for positioning a pier or the like relative to a body of water are generally inconvenient, complicated and difficult to operate, and not designed to self-adjust in response to the rise or fall of the water surface. It is desirable to provide a technique for conveniently and readily adjusting the configuration of an object, such as a pier or the like, relative to the surface of a body of water, either selectively or in response to the change in height of the surface of the water. It is also desirable to provide a locking mechanism that may close automatically if the deck of the pier is not sufficiently supported, and that the locking mechanism is operable to close even while the deck is being raised or lowered. The present invention provides these capabilities.